If you are using the AP Import under AP Utilities just press the green "?" .  Under related topics there is File Structure Formats.  That has your layout information.  Your posts are giving bare bones information.  It's always better to give more info.

Keep in mind that using the older import utilities may have less functionality as they are not necessarily updated as as more fields became/become available over time.  The DI module imports will generally have the most up-to-date import capabilities.  This is not a sales message, just a reflection of the product avoiding duplicate work once DI was introduced.  Internally here, we generally use the DI module for importing work.  

As pointed out by John, it is possible to use the DI infrastructure that already exists in the database to obtain DI functionality if one has the technical skills and the patience, or access to one of the many fine partners out there.

Keep in mind that using the older import utilities may have less functionality as they are not necessarily updated as as more fields became/become available over time.  The DI module imports will generally have the most up-to-date import capabilities.  This is not a sales message, just a reflection of the product avoiding duplicate work once DI was introduced.  Internally here, we generally use the DI module for importing work.  

As pointed out by John, it is possible to use the DI infrastructure that already exists in the database to obtain DI functionality if one has the technical skills and the patience, or access to one of the many fine partners out there.